Project description:Tail fat in sheep (Ovis aries), has evolved mainly in response to cold weather for better energy storage. As things stand, too much tail fat in sheep can lead to a reduction in feed utilisation and is also unpopular with consumers due to the excessive fat content in the tail of sheep. Therefore, the need to find the mechanism of tail fat formation is obvious. In this study, we elected to utilise Kazakh sheep, prolific Suffolk sheep, and their hybrid F2 generation as research objects. Sheep transcriptome sequencing technology was employed to screen and explore target candidate genes related to sheep tail fat deposition. Comparison with RNA-seq data from fat-tailed and thin-tailed tissue, the LncRNA-mRNA-miRNA axis was identified as main functional pathway in the formation of fat in tail. Our results offer valuable insights into the fat deposition of sheep and provide a significant genomic resource for future genetic studies and the enhancement of genome-assisted breeding in sheep and other domestic animals.
Project description:Body axis patterning in vertebrates is controlled by HOX genes during embryogenesis, with their expression gradients defining spatial identity along the anterior–posterior axis. While their developmental roles are well known, less is understood about their persistence and function in adult tissues. Tail length in sheep provides a model for studying the phenotypic effects of HOX gene variants. We used Improved Jezersko–Solčava sheep, which segregate for both tail length and HOXB13 promoter variants, to examine genotype–phenotype associations. The HOXB13 genotype was the main determinant of adult tail length, acting primarily by modulating caudal vertebral number. RNA‑seq and qPCR analyses revealed a clear anterior–posterior HOXB13 expression gradient in adult tail skin and bones, with stronger distal expression in short‑tailed animals. These results provide in vivo evidence that spatially patterned HOX gene expression persists in adulthood, suggesting that residual developmental programs may maintain regional identity in adult tissues.
Project description:Effective management and control of parasitic infections on farms depends on their early detection. Traditional serological diagnostic methods for Fasciola hepatica infection in livestock are specific and sensitive, but currently the earliest detection of the parasite only occurs at approximately three weeks post-infection. At this timepoint, parasites have already entered the liver and caused the tissue damage and immunopathology that results in reduced body weight and loss in productivity. Here, we investigated whether the differential abundance of micro(mi)miRNAs in sera of F. hepatica-infected sheep has potential as a tool for the early diagnosis of infection. Using miRNA sequencing analysis, we discovered specific profiles of sheep miRNAs at both the pre-hepatic and hepatic infection phases in comparison to non-infected sheep. In addition, six F. hepatica-derived miRNAs were specifically identified in sera from infected sheep. Thus, a panel of differentially expressed miRNAs comprising four sheep (miR-3231-3p; miR133-5p; 3957-5p; 1197-3p) and two parasite miRNAs (miR-124-3p; miR-Novel-11-5p) were selected as potential biomarkers. The expression of these candidates in sera samples from longitudinal sheep infection studies collected between 7 days and 23 weeks was quantified using RT-qPCR and compared to samples from age-matched non-infected sheep. We identified oar-miR-133-5p and oar-miR-3957-5p as promising biomarkers of fasciolosis, detecting infection as early as 7 days. The differential expression of the other selected miRNAs was not sufficient to diagnose infection; however, our analysis found that the most abundant forms of fhe-miR-124-3p in sera were sequence variants (IsomiRs) of the canonical miRNA, highlighting the critical importance of primer design for accurate diagnostic RT-qPCR. Accordingly, this investigative study suggests that certain miRNAs are biomarkers of F. hepatica infection and validates miRNA-based diagnostics for the detection of fasciolosis in sheep.